leland yee was in chicago hoping to revive it. >> i think there is an assault weapon ban. the law was passed, signed by the manufacturer, however they found a loophole in the law by modifying these weapons with a bullet button. >> student isn't giving up his legal weapon. >> prior to coming here, all my friends are all these shootings, what do you think about it, i said all these shootings i personally think that, you know, i need to have -- invest in a good gun. >> always keep the gun pointed in the safest possible direction. >> reporter: in a classroom he isn't staunched against tighter gun regulation but he feels the back ground check should include mental health issues. . >> we want people without issues to get a gun. if they choose it have one. >> reporter: jade hernandez, ktvu channel 2 news. >> the reason for the massacre may never be known but as we told you last night details are emerging about adam lanza's mental health. ktvu's health and science editor john fowler joins us to explain what is aspergers syndrome. john? >> reporter: in the last 24 hours, friends sa